DataAccess.java

package jpaoletti.jpm.core;

import java.util.List;

/**
 * An entity data access offers the basic methods to operate over the data
 * source of an entity.
 * 
 * @author jpaoletti
 * */
public interface DataAccess {

    /**
     * Setter for the entity
     */
    public void setEntity(Entity entity);

    /**
     * Getter for the entity
     */
    public Entity getEntity();

    /**
     * Getter for the id of an object. If entity.idField is null, null is 
     * @param ctx The context
     * @param instanceWrapper The instance to identify
     * @param id The string representation of some identification.
     */
    public InstanceId getInstanceId(PMContext ctx, EntityInstanceWrapper instanceWrapper) throws PMException;

    /**Get an item from data source an item identified by the property=value
     *
     * @param ctx The context
     * @param property The property to look up
     * @param value The value of the property that must be looked for.
     * @return The object or null of not found
     * @throws PMException
     * */
    public Object getItem(PMContext ctx, String property, String value) throws PMException;

    /**
     * Get an item by id, if the entity has idField. If not, null is returned.
     *
     * @param ctx The context
     * @param instanceId The value of the id that must be looked for. @see InstanceId
     * @return The object or null of not found
     * @throws PMException
     * */
    public Object getItem(PMContext ctx, InstanceId instanceId) throws PMException;

    /**Get a filtered list of items from data source with the given items
     * 
     * @param ctx The context
     * @param filter The filter of the list
     * @param sort List sort
     * @param from The starting index of the list
     * @param count The maximum number of resultant items
     * @return The list of items
     * @throws PMException
     * */
    public List<?> list(PMContext ctx, EntityFilter filter, ListFilter lfilter, ListSort sort, Integer from, Integer count) throws PMException;

    /**Get the total number of items of the entity
     * @param ctx The context
     * @return Item total count
     * @throws PMException
     * */
    public Long count(PMContext ctx) throws PMException;

    /**Removes the object from data source
     * 
     * @param ctx The context
     * @param object The object to remove
     * @throws PMException
     * */
    public void delete(PMContext ctx, Object object) throws PMException;

    /**Updates the given object
     * 
     * @param ctx The context
     * @param instance The modified object
     * @throws PMException
     * */
    public void update(PMContext ctx, Object instance) throws PMException;

    /**Adds the object to the data source
     * 
     * @param ctx The context
     * @param instance The new object
     * @throws PMException
     * */
    public void add(PMContext ctx, Object instance) throws PMException;

    /**Synchronize the referenced object with the data source
     * 
     * @param ctx The context
     * @param o The object to refresh
     * @return Fresh object
     * @throws PMException
     * */
    public Object refresh(PMContext ctx, Object o) throws PMException;

    /**Creates a new instance of the specific class of this data access
     * 
     * @param ctx The context
     * @return the new filter
     * @throws PMException
     * */
    public EntityFilter createFilter(PMContext ctx) throws PMException;
}